Gunsight



R. W. JONES Dec. 3, 1963 GUNSIGHT 2 Sheets-Sheet 1 Filed Nov. 9, 1962jay. 1

INVENTOR. fierf Willa Mes p I shown by FIG; 4;

- FIG. 6 is a typical schematic diagramshowing the relative area withinwhich hits are obtained for givencriteria;

Un ted S at s P t n 3,112,566 GUNSIGHT Robert Will Jones, 3900 Glenwood,Fort Worth, Tex. Filed'Nov. 9, 1962, Ser. No. 238,319

3 Claims. (Cl. 33-47) V 1 My invention relates to gunsights,'and moreparticularly to gunsights'of a type suitable for use with a gun having ashot" pattern which diverges with distance from the gun muzzle, as forexample in the case of a shotgun.

Such guns are often employed to hunt game birds such as ducks, geese,quail and the like.v Since such game is ordinarily shot while in flight,the problems of flight speed, target distance, flight course, shotpattern, and, ultimately,

.lead angle are involved. Inmany cases, the lead angle is determined byestimation based mostly on the hunters experience. Various types ofgunsights have been devised to aid the hunter in his aiming techniqueand to thereby improve his eifectiveness. While some such gunsights ofthe prior art of which I am aware have been partially effective, yetthey still leave much to be desired.

It is accordingly an object of my invention to provide an improved sightforuse with guns of the diverging-shot pattern type. i

' Another object of my invention is to provide an improved gunsightfor'use with guns ofv the diverging shot pattern type, which sight willenable the hunter to provide'the proper lead angle when shooting atobjects in flight.

Another object of my invention is to provide a gunsight for use withguns of the diverging shot pattern type, Whereina visual, reference isestablished which the shooter may apply to obtain an optimum number ofhits within the range of the shells fired.

These and other objects are elfected by my invention as will beiapparentfrom the following description taken in accordance with the accompanyingdrawings forming a part of this application, in which: V r FIG. 1 is aschematic side elevational view showing a gunsight in accordance with apreferred embodiment of;v iny invention,,mounted on a gun; I

'FIG. 2 isan enlarged schematic longitudinal section I view of the sightof FIG. 1; 1

FIG. 3 is an end elevation view of the sight of FIG. 1

I with portions of the gun omitted;

FIG. 4 is a schematic'diagram showing the relation of a typical targetto the sight visual image for three different ranges; 7 I I FIG. 5 is aschematic diagram showing the relation of theshot pattern to the sightvisual image for the ranges and FIG. 7 is a schematic diagram showingthe average percentage of hits plotted against various sight divergenceratios.

Referring-now to the drawings, and particularlyto I -FIGS. l and 2, itwill be seen that the gunsight 11 is simply a hollow cone frustum. Thesight is preferably made of thin metal material, for example steel orbrass, although it could be plastic. The primary requirement is that thesight should have the proper relative size and shape, the material usedbeing of secondary importance so long as it is satisfactory fromthestandpoints of economy, quality, and durability. The sight maybe fixed'onto the gun 13 in any suitable manner, for example, by screw clamps'15 as shown by FIGS. '2 and 3. The sight 11is fixed to the gun 13 so asto be above the rear end portion of the gun barrel and with the sightcentral axis parallel to the gun bore, and with the sight cone divergeing in the forward direction.

, 3,112,566 Patented Dec. .3, 19 3 The characteristic feature of myinvention is a; frusto conical gunsight having an optimum sightdivergence resent the visible indicium in idealized forin as it wouldappear to the shooter for three different ranges, as he looks throughthe gunsight in the normal manner. The shooter would not of courseobserve anydetails of the target. FIG. 4A shows atypical target 23 at arelatively close range; FIG. 4B at an intermediate range; and FIG. I

In each case it is im-' 40 at a relatively distant range. portant tonotice that the visible indicium which the shooter observes is acircular ring. The proper-application of this visible indicium will bedisclosed hereinafter.

In FIGS. 5A, 5B and 5C there is shown in generalized form the typicalshot pattern 25in relation to the visible indicium at the same ranges ofFIG. 4. The shot pattern illustrated in FIG. -5 is typical of the typeproduced by a full-choke gun. V 7

Many observations of various, types of game birds in flight hasestablished the fact that their maximum flight speeds are between '35and 72 miles per hour. Now, if reasonable adjustments are made: to allowfor group flight conditions and for the fact that jumped birds seldomreach their normal flight speeds beforethe huntershoots, then theaverage flight speeds of these same types-of game birds at the time ahunter shoots is found to be between 30 and 45 miles per hour.

At the present'time most shotgun barrels and choke devices are mosteffective at ranges between 19'and 50 yards. The shotgun shells,aspresently manufactured; have muzzle velocities and energies which arereasonably constant for a quantity of powder and a size of shot. It isWell known, also, that the diameter ofthe' field of view, as observed,through a.-frusto-conical gunsight, is different than the calculateddiameter for any particular range and angle of divergenceof the cone. Ithas occurred to the' applicant that it is possible to determine thenumber of hits on a target of a given speed-v and'direce tion when thecharacteristics of the shot shell, the sight divergence ratio, the shotpattern diameten'the elapsed time for human and mechanical action,theignition time,

might have a /81" diameter smaller end anda diame- V ter larger end. Inaccordance with a preferred embodiment of my invention, atypical sightmay have a length of 7 an inside diameter of A at the'small end and 1 atthe large end, and consequently a divergence ratio of-.0.965.

Applicant has made many diagrams, FIG. '6 being typical of such, whichshow the area within which hits are obtainable for established criteria.When the area Within which hits are obtained is divided by the areaWithin Y From this family of diagrams, the diagram of FIG. 7 is preadily obtainable. It represents a single average diagram of the familyof diagrams and is conveniently plotted as shown in FIG. 7'.

The established criteria on which the plot of FIG. 6 is based is: asight divergence ratio of 0.965 to one foot; a shell having thecharacteristics 12 ga., 3 x 1%. x 7 /2 0. and and effective range of to45 yards; a gun having a full choke; and a bird speed of miles per hour.The elapsed time for human and mechanical action, the ignition time andthe barrel time are, for this purpose, considered constant criteria. Theapplicant has found that under these criteria a shooter may expect toscore hits on birds that are within the area defined by the linesconnecting points NPRMN. For purposes of illustration, assume that atarget is at point T and is moving on a flight course oriented at anangle of 45 to and directed away from the shooter. The distance betweenthe shooter and point T is 30 yards, which is within the range of theshell used. The shooter then may expect to hit this target. In likemanner, the shooter may expect hits on targets anywhere within the areaNPRMN. Now, this area is only a proportionate part of the semi-annulararea defined by lines connecting points EFGH, and it is the area EFGHwhich represents the maximum area within which hits are possible. Hence,the ratio of area NPRMN to area EFGH is the ratio of expected hits,which, of course, may readily be expressed as a percentage of hits. Inthe instant case, shown by FIG. 6, the area NPRMN is about 53 percent ofthe area EFGH. And so, the shooter may expect to obtain 5 3 percenthits.

It has been explained hereinbefore that the diagram of FIG. 7 is anaverage curve obtained from numerous plots similar to FIG. 6. Thesignificance of FIG. 7 is apparent. Firstly, it shows that thepercentage of hits varies markedly with changes in divergence ratio;secondly, it shows that a small change in the divergence ratio value mayproduce a large difference in the percentage of hits; thirdly, it showsthat the percentage of hits reaches a rather distinct maximum; andlastly it shows that the greatest percentage of hits occurs within acritical range of sight divergence values which may be considered asbeing between about to one foot and substantially 1 4 to one foot; themaximum being very close to 7 to one foot. It is to be noted thatoutside this critical range, the change in percentage of hits is quiterapid, particularly above the 1 value. It may also be noted that thepercentage of hits does not vary greatly between the values of A3" to 1It is clear, therefore, that the gunsight of my invention may have asight divergence ratio between A and 1 to the foot. The optimum gunsightwould have a sight divergence ratio of substantially to one foot.

Now, in using the gunsight of my invention in the preferred manner, itis only necessary that the shooter sight and track a target in flight insuch a way that, when he pulls the trigger, the target is disposed on adiameter of and advancing toward the center of the visual image pattern17, 19 and 21. When a shooter properly uses a gunsight made inaccordance with my invention, he may expect to achieve about 53 percenthits on game bird targets moving at average flight speeds within therange of normally selected shells.

It should be apparent therefore that I have provided an improved andeffective gunsight which, when used on guns producing a diverging shotpattern, enables the shooter to sight and place the target quickly andeasily in proper relation to the visual image pattern so as to obtainthe maximum number of percentage of hits.

While I have shown my invention in only one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof.

I claim:

1. For use with a firearm of the shotgun type having a diverging shotpattern and for game bird targets of types that are normally moving atspeeds of between 30 and 45 miles per hour when fired upon at rangesnormally between 20 and 50 yards and with ammunition of the typenormally selected for such targets, a sight comprising: a hollow rightcircular conical frustum adaptable for mounting on said firearm so as tobe diverging toward the muzzle end of said firearm, said conical frustumhaving dimensions substantially proportional to a frustum seven incheslong, seven-sixteenths inch diameter at the smaller end and one inchdiameter at the larger end, said sight to be mounted on said firearm inthe position relative to the normal position of the users eye that willproduce for the user a visible indicium in the form of a circular ringof apparent minimum thickness.

2. For use with a firearm of the shotgun type having a diverging shotpattern and for game bird targets of types that are normally moving atspeeds of between 30 and 45 miles per hour when fired upon at rangesnormally between 20 and 50 yards and with ammunition of the typenormally selected for such targets, a sight comprising: a hollow rightcircular conical frustum adaptable for mounting on said firearm so as tobe diverging toward the muzzle end of said firearm, said sight conehaving a sight divergence ratio in the range between seven-eighths andone and one-thirty-second inches per foot, said sight to be mounted onsaid firearm in the position relative to the normal position of theusers eye that will produce for the user a visible indicium in the formof a circular ring of apparent minimum thickness.

3. For use with a firearm of the shotgun type having a diverging shotpattern and for game bird targets of types that are normally moving atspeeds of between 30 and.45 miles per hour when fired upon at rangesnormally between 20 and 50 yards and with ammunition of the typenormally selected for such targets, a sight comprising: a hollow rightcircular conical frustum adaptable for mounting on said firearm so as tobe diverging toward the muzzle end of said firearm, said sight having asight divergence ratio in the range between three-quarters inch and oneand one-thirty-second inches per foot, said sight to be mounted on saidfirearm in the position relative to the normal position of the users eyethat will produce for the user a visible indicium in the form of acircular ring of apparent minimum thickness.

References Cited in the file of this patent UNITED STATES PATENTS2,586,807 Fowler Feb. 26,1952

1. FOR USE WITH A FIREARM OF THE SHOTGUN TYPE HAVING A DIVERGING SHOTPATTERN AND FOR GAME BIRD TARGETS OF TYPES THAT ARE NORMALLY MOVING ATSPEEDS OF BETWEEN 30 AND 45 MILES PER HOUR WHEN FIRED UPON AT RANGESNORMALLY BETWEEN 20 AND 50 YARDS AND WITH AMMUNITION OF THE TYPENORMALLY SELECTED FOR SUCH TARGETS, A SIGHT COMPRISING: A HOLLOW RIGHTCIRCULAR CONICAL FRUSTUM ADAPTABLE FOR MOUNTING ON SAID FIREARM SO AS TOBE DIVERGING TOWARD THE MUZZLE END OF SAID FIREARM, SAID CONICAL FRUSTUMHAVING DIMENSIONS SUBSTANTIALLY PROPORTIONAL TO A FRUSTUM SEVEN INCHESLONG, SEVEN-SIXTEENTHS INCH DIAMETER AT THE SMALLER END